Process of fatliquoring



Patented Oct. 18, 1932 UNITED STATES PATENT ornca IAN C. SOMERVILLE, OF FOX CHASE, PENNSYLVANIA, ASSIGNOR TO BOHM A: HAAS 'COMPANY, A CORPORATION OF DELAWARE rnocnss or rarmononme 1% Drawing. Application filed June 20,

This invention relates to a new fatliquoring leather.

V In the course of conversion of raw hides or skins into leather, the natural grease and 5 oils of the skin are largely removed. If the skin at the end of the tanning process were dried out without further treatment a hard and unyielding piece of leather'would result. The characteristic flexibility of leath- 39 er is secured by a lubrication of the fibres by replacement of some of the grease which has been removed. This is carried out by treating the tanned and probably coloured skin with oils just previous to drying out. In some cases these are applied by oiling ed, that is by smearing oil on the wet surface, but it is often found more convenient to apply the oil in a dispersed form in a drum, the fatliquoring process.

The quality of the leather obtained is largely determinel by the type of oil used, and by its final distribution in the skin.

In order to secure a uniform application of oil to the leather it is essential to have the oil in a well dispersed form in the liquor in which the skins are drummed. This is secured in practice generally in one of two ways.

In the first a special type of solubilized oil is employed. These are almost entirely obtained by treatment of the common leather oils, such as cod oil, neats-foot oil, castor oil, with sulphuric acid, in such a way that products soluble in water or readily dispersable in water are obtained. These give excellent process of results so far as uniformity of application is concerned. It is recognized in practice however that some desirable types of leather can not be secured by the use of such oils alone.

In the second method an oil which is insoluble in water is applied to the skin by first emulsifying it in the aqueous liquor used, and applying this to the skin. This emulsification is commonly carried out in one of three ways:

(a) A mixture of solubilized oil and straight oil is employed. The solubilized oil acts as an emulsifier for the insoluble oil.

(2)) N a t u r ally occurring emulsifying 59 agents such as egg yolk, and certain proteins,

1930. Serial No. 432,709.

are used to emulsify the straight oil. In some cases egg yolk by itself is used, as this contains oily matter already emulsified.

The benefits of this method are well recognized in the leather industry, but it is not used as frequently as its merits indicate on account of the expense of egg yolk.

(c) The straight oil is emulsified by soap. In many cases this gives an excellent emulsion However this type of emulsion is not 60 well suited for application to leather. Both vegetable and chrome leather in the finished state often contain enough acid to cause immediate breaking down of a soap emulsion, with the consequent danger of uneven deposition of oil on the leather.

All of these methods are in common use in tannery practice.

I have now discovered a process for fat liquoring which utilizes the principal feature w of method (5), namely a thorough emulsification of straight oil, and at the same time overcomes the objections to method (0), in that the emulsions are stable to amounts of acid exceeding those normally found in the 7 fatliquoring process.

By use of'emulsifying agents of the type described below I have found it possible to prepare stable emulsions of leather oils which give excellent results in fa-tliquoring of 0 leather.

lhese materials consist of salts of tertiary alkyl'amines or" the type wherein R represents a straight chain of at least 8 carbon atoms fully saturated with hydrogen, R and R short carbon chains containing not more than 4 carbon atoms, or quaternary alkyl ammonium salts of the type wherein R represents a long straight chain of at least 8 carbon atoms fully saturated with hydrogen, R R R short carbon chains containing not more than 2 carbon atoms, and S one equivalent of an acid radical.

5 efiective in making emulsions of this type.

For instance, it is not necessary to have a straight carbon chain as the long chain art.

Diethyldicaprylamine salts were foun to possess excellent emulsifying properties.

Further, other atoms than carbon can bepresent in the chain. Salts formed from diethylaminoethyloleylamide or from trimethylaminoethyloleylamide where the lon chain includes a nitrogen atom are also e ective.

replaced b derivatives. such as hydroxy substituted al 1 groups. Salts from such com pounds as diethanoloctadecylamine or triethanolcetylamine are very useful. Finally, it is possible to utilize compounds which have an aryl groupin place of one of the alkyl groups; diethylbenzylcetylammonium chloride forms good emulsions with oils, have excellent fatliquoring properties. I can use a series of difierent salts of the amines though the most convenient arethose with the simple mineral acids such as hydrochloric, sulphuric, phosphoric, or of the soluble organic acids such as acetic, oxalic, citric and the like. The oils used may be selected in accordance with the nature of the skin to be fatliquored, but the ordinary leather oils are found most suitable, namely cod oil and neats-foot oil. Other oils may also be used, such as olive oil, castor oil, or mixtures of these oils, e. g. with mineral oil.

'I havefound it possible to control the distribution of the oil in the leather by means of the stability of the emulsion. When a soft fier to oil is used, when a greater amount of penetration is obtained. A similar resultv may be secured by the addition of'a small quantity of acid to the emulsifier. When a leather of greater firmness is desired a smaller amount of emulsifier relatively to oil is used, and no acid added; the oil is then confined to the surface layers of the skin, and the resulting leather has a fine temper.

' The method of application of this new process is illustrated by the examples given below, but the invention is in no way confined to these examples:

Ema/mple 1 100 lbs. of chrome tanned calfskins in the blue are coloured black and fatliquored as in the regular process at 120 F. with an emulsion made up as follows:

2 lbs..neats-foot oil is added with vigorous stirring to 2 lbs. of a 10% solution of the hydrochloride of diethyloctylamine, warmed to 120 F. The resulting creamy solution is diluted with an equal volume of water at 120 Also, the short chain alkyl radicals may be which leather is desired a high proportion of emulsi- F. and added to the skins in the rotating drum through the axle.

' The skins may be finished up as usual.

Example 2 100 lbs. of chrome tanned kidskins which have been neutralized and coloured are fatliquored with an emulsion prepared as follows:

3 lbs.neats-foot oil are added with vigorous stirring to 3 lbs. of a. 1% solution of the hydrochloride of diethyllaurylamine at 120 F. The resulting creamy emulsion is diluted with an equal volume of water at 120 F. and added to the skins in the rotating drum.

Example 3 100 lbs. of chrome tanned sheepskins are fat-liquored with an emulsion prepared as follows:

2 lbs. castor oil are added with vigorous stirring to 5 lbs. of a 1% solution of the sulphate of dimethylcetylamine at 120 F. to which has been added .005 lb. sulphuric acid. The resulting creamy emulsion is diluted with an equal volume of water at 120 F. and added to the skins in the rotating drum.

Ewample 4 100 lbs. of chrome tanned sheepskins which have been coloured are fat liquored at 120 F. with an emulsion prepared as follows:

2 lbs.neats-foot oil are added with vigorous stirring to 10 lbs. of a solution of the hydrochloride of diethylcerylamine at 120 F. The mixture is added to the skins in the rotating drum without further dilution.

Example 5 100 lbs. of chrome tanned side leatuer which has been coloured is fatliquored with an emulsion prepared as follows:

3 lbs. cod oil are added with vigorous stirring to 6 lbs. of a solution of diethyloctadecylamine phosphateat 120 F. This solution is made by addition of two equivalents of phosphoric acid for each molecule of amine.

The resulting creamy emulsion is diluted with an equal volume of water at F. and added to the skins in the rotating drum.

Example 6 100 lbs. of vegetable tanned furniture leather is fatliquored at 100 F. with an emulsion prepared as follows:

5 lbs. cod oil are added with vigorous stirring to 10 lbs, of a. 1% solution of diethyldicaprylamine oxalate at 100 F. The resulting creamy emulsion is diluted with an equal volume of water at 100 F. and added to the skins in the rotating drum.

Example 7' E mample 8 100 lbs. of chrome tanned calfskins which have been coloured are fatliquored at 120 F. with an emulsion prepared at follows:

2 lbs. cod oil are added .with vigorous stirring to 4 lbs. of a 1% solution of triethanolcetyl ammonium bromide at 120 F. The resulting creamy emulsion is diluted with an equal volume of water at 120 F. and added to the skins in the rotating drum.

Ewample 9 100 lbs. of vegetable tanned sheepskins are fatliquored at 100 F. with an emulsion prepared as follows:

2 lbs. neats-foot oil and 1 lb. olive oil are mixedand added with vigorous stirring to 3 lbs. of a 1% solution 0t diethylbenzylcetyl ammonium chloride at 105 F. The resulting creamy emulsion is diluted with an equal volume of water at 105 F. and added to the skins in the rotating drum.

Example 10 100 lbs. of chrome tanned sheepskins are coloured and fatliquored at 120 F. with an emulsion prepared as follows:

2 lbs. neats-foot oil and 1 lb. Nujol are mixed and added with vigorous stirring to 6 lbs. of a 1% solution of trimethylcetyl ammonium bromide at 120 F. The resulting creamy emulsion is diluted with an equal volume of water at 120F.and added to the skins in the rotating drum.

Having set forth and illustrated the nature of this invention 1 claim:

1. the preparation of leather the step which comprises applying to the leather an oil in the form of an emulsion stabilized by a compound selected from the class consisting of tertiary and quaternary amine salts of the general formulas wherein R represent a long chain radical of at least 8 carbon atoms R and R radicals of not more than 4 carbon atoms of the nature of alkyl or substituted alkyl groups, R

, represents an alkyl, aryl, or aralkyl radical,

S represents one equivalent of an acid. radical, and H represents the hydrogen radical. V 2. The process of fatliquorm leather which consists in the application 0 a water- 73 insoluble oil in the form of an emulsion stabilized by a compound selected from the class consisting of tertiary and quaternary amine salts of the general formulae where R represents a long chain radical of at least 8 carbon atoms, R and R represent radicals of not more than 4 carbon atoms of the nature of alkyl or substituted alkyl groups, R represents. an alkyl, aryl, or aralkyl radical, S represents one equivalent of an acid radical, and H represents the hydrogen radical. I

8. The process of fatliquoring leather which consists in the application of a waterinsoluble oil in the form of an emulsion stabilized'by a compound selected from the class consisting of tertiary or quaternary amine salts of the general formulae Where R represents a long chain alkyl radi- 10o cal of from 8 to 26 carbon atoms, R and R represent radicals of not more than 4 carbon atoms of the nature of alkyl or substituted alkyl groups, R represents an alkyl, aryl, or aralkyl radical, S represents one'equivalent of an acid radical, and H represents the hydrogen radical.

4c. The process of fatliquoriug leather which consists in the application of a waterinsoluble oil in the form of an emulsion stabilized by a compound selected from the class consisting of tertiary and quaternary amine salts of the general formulae where R represents a long chain alkyl radical of from 8 to 26 carbon atoms, R and R represent radicals of not more than 4 carbon atoms of the nature of alkyl or substituted alk-yl groups, R represents the benzyl radical, S represents one equivalent of an acid radical, and H represents the hydrogen radical.

5. The process of fatliquoring leather which cons sts in the application of a waterinsoluble oil in the form of an emulsion stabilized by a compound selected from the class 1:30

consisting of tertiary amine salts of the general formula where R represents a long chain alkyl radical offrom 8 to 26 carbon atoms, R and R represent radicals of not more than 4 carbon 1 atoms'of the nature of alkyl or substituted alkyl grou s, S represents one equivalent of insoluble oil in the form of an emulsion sta-. bihzed by a compound selected from the class.

consisting of tertiary amine salts of the general formula where R represents a long chain alkyl radical of from 8 to 26 carbon atoms, R and R represent alkyl radicals of not more than 4 carbon atoms, S represents one equivalent of an acid radical, and H represents the hydrogen radical.

7. The process of fatliquoring leather which consists in the application of a waterinsoluble leather oil in the form .of an emulsion stabilized by an amine salt of the formula dl-N R s where R represents the cetyl radical, R and R are alkyl groups of not more than two carbon atoms, S represents one equivalent of an acid radical, and H represents the hydrogen radical.

8. The process of fatliquoring leather which consists in the application of a waterinsol'uble leather oil in the form of an emulsion stabilized by a salt of diethylcetylamine.

9. The process of fatliquoring leather which consists in the application of a waterinsoluble leather oil in the form of an emulsion stabilized by means of diethylcetylamine sulphate.

10. The process of fatliquoring leather which comprises applying a water-insoluble leather oil in the form of an emulsion stabilizcd by means of (liethanoloctadecylainine hydrochloride.

11. The process of fatliquoring leather which comprises applying a water-insoluble leather oil in the form of an emulsion stabilized by means of trimethyllaurylammonium bromide.

12. In the preparation of leather the step which comprises the application of a Water insoluble oil in the form of an aqueous emulsion havin apI-I of less than 5.

13. In t e preparation of leather the step which comprises the application of a water insoluble oil in the form of an emulsion 7 which is more acid than the leather being treated.

14. In the preparation of leather the step which comprises the application of an'oll' in the form of an emulsion stabilized by a. compound of the class consisting of salts of tertiary and quaternary amines.

IAN G. SOMERVILLE. 

